If you don't get it, the idea is if you go bathroom #1, and it's yellow, don't flush it, just wait for the next person. However, if bathroom #2, and it is brown (or whatever color it might be) do flush and get it away. I'm sure it is a lovely idea and all, save the planet right? But really? Is the planet in that bad of shape?
I guess it is something you have to get use to. I work with someone who does this, and it's a little odd to walk into use the bathroom and see that sitting there. I'm getting more use to it, but I do not pass it on. It is one of those things that in public you wonder if the toilet is actually working or not. And some mornings, for unknown reasons, the water pressure isn't working, so we all do this by force.
I guess what I'm saying is it is a great idea, possibly. If you don't mind seeing what other people have left in there, and probably in the privacy of your own home. But if you can't, and the water is cheap, why not just get all of the waste out of the house as soon as possible, isn't that why indoor plumbing was invented anyways?